LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 1995 >> SC 400 >> Repair and Diagnosis >> Body & Frame >> Seats - Power W/Memory >> Circuit Testing >> +B Power Source Circuit Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

+B Power Source Circuit Test

NOTE: Use this procedure to check for problems in circuit between driver's power seat ECU and DOOR fuse.
  1. Check DOOR fuse. If DOOR fuse is open, repair short to ground in circuit between DOOR fuse and driver's power seat ECU, or between driver's power seat ECU and seat motors. If DOOR fuse is okay, ensure ignition is off. At driver's seat, remove bolts for front vertical adjuster.
  2. Lift front end of seat cushion slightly for access to driver's power seat ECU (DO NOT  lift too far; harness clamp may come loose). Remove driver's power seat ECU, but leave wiring harness connectors attached.
  3. At connector "A" of driver's power seat ECU, connect voltmeter negative lead to terminal No. 1, and connect positive lead to terminals No. 5 and 14 (backprobe connector). See Fig 1. If battery voltage is present, check next item listed under TROUBLE SHOOTING .
  4. If battery voltage is not present, measure resistance between terminal No. 1 and ground. If resistance is one ohm or more, repair open circuit. If resistance is less than one ohm, repair circuit between battery and driver's power seat ECU.
Fig 1: Power Seat ECU Wiring Harness Connector Terminal ID
G94F47568Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002